From: | Fabien COELHO <coelho(at)cri(dot)ensmp(dot)fr> |
---|---|
To: | Mitsumasa KONDO <kondo(dot)mitsumasa(at)gmail(dot)com> |
Cc: | PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: gaussian distribution pgbench |
Date: | 2014-07-02 09:05:56 |
Message-ID: | alpine.DEB.2.10.1407021046080.22369@sto |
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Lists: | pgsql-hackers |
Hello Mitsumasa-san,
> And I'm also interested in your "decile percents" output like under
> followings,
> decile percents: 39.6% 24.0% 14.6% 8.8% 5.4% 3.3% 2.0% 1.2% 0.7% 0.4%
Sure, I'm really fine with that.
> I think that it is easier than before. Sum of decile percents is just 100%.
That's a good property:-)
> However, I don't prefer "highest/lowest percentage" because it will be
> confused with decile percentage for users, and anyone cannot understand
> this digits. I cannot understand "4.9%, 0.0%" when I see the first time.
> Then, I checked the source code, I understood it:( It's not good
> design... #Why this parameter use 100?
What else? People have ten fingers and like powers of 10, and are used to
percents?
> So I'd like to remove it if you like. It will be more simple.
I think that for the exponential distribution it helps, especially for
high threshold, to have the lowest/highest percent density. For low
thresholds, the decile is also definitely useful. So I'm fine with both
outputs as you have put them.
I have just updated the wording so that it may be clearer:
decile percents: 69.9% 21.0% 6.3% 1.9% 0.6% 0.2% 0.1% 0.0% 0.0% 0.0%
probability of fist/last percent of the range: 11.3% 0.0%
> Attached patch is fixed version, please confirm it.
Attached a v15 which just fixes a typo and the above wording update. I'm
validating it for committers.
> #Of course, World Cup is being held now. I'm not hurry at all.
I'm not a soccer kind of person, so it does not influence my
availibility.:-)
Suggested commit message:
Add drawing random integers with a Gaussian or truncated exponentional
distributions to pgbench.
Test variants with these distributions are also provided and triggered
with options "--gaussian=..." and "--exponential=...".
Have a nice day/night,
--
Fabien.
Attachment | Content-Type | Size |
---|---|---|
gaussian_and_exponential_pgbench_v15.patch | text/x-diff | 23.5 KB |
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